JP4667869B2 - Drive mechanism for generating oscillating motion in small appliances - Google Patents

Abstract

The invention relates to a drive device for the generation of an oscillating movement for at least one working unit (9) in a small electrical appliance. Said drive device comprises a coil (4), for generation of a magnetic field, which emanates from a first drive component (1) and interacts with a second drive component (2), movably arranged in the small electrical appliance, such as to set the second drive component (2) in an oscillating movement. The first drive component (1) is movably embodied in the small electrical appliance such as to carry out an oscillating movement in counter-phase to the second drive component (2). The drive device comprises a coupling element (17), by means of which a rigid coupling for both drive components (1, 2) in a direction parallel to the movement direction of both components and an elastic coupling between the both drive components (1, 2) in a direction perpendicular thereto can be achieved.

Description

  The invention relates to a drive mechanism for generating an oscillating movement of at least one actuation unit of a small appliance. The invention further relates to a small appliance equipped with such a drive unit. Such small appliances include in particular electric shavings and electric toothbrushes.

  A vibrating armature drive for an electric shaving with a vibrating motion of the shaving blade is known from German publication DE1151307A. Known vibrating armature drives include a U-shaped electromagnet fixedly formed in the shaving device housing. Arranged in the vicinity of the poles of the electromagnet are operating armatures, and each vibration compensating armature is arranged generally symmetrically on each side of the operating armature. The operating armature and the compensating armature are suspended from each other by U-shaped leaf springs. During operation, the operating armature that drives the shaving blades vibrates parallel to the pole face of the fixed electromagnet. The compensating armature oscillates in anti-phase to prevent as much as possible the vibration of the operating armature from being transmitted to the shaving device housing.

  German publication DE 19680506 T1 discloses an electric shaver with a linear vibration motor. The linear vibration motor includes a fixed electromagnet and a plurality of movable members set to vibrate in mutually opposite phases by the electromagnet. The electromagnet is fixedly screwed to the shaving device chassis. The movable member is suspended from the chassis by a leaf spring. The leaf spring has a plurality of slits so that each movable member can be moved in the opposite direction. In order to maintain the opposite phase of the movable member, the members are interconnected by a linkage mechanism. The link mechanism is attached to a fixed shaft for rotation.

  An electric shaver with a linear drive mechanism having a hollow cylindrical stator with electromagnetic coils is known from German publication DE 197881664C2. Disposed within the stator are two movable members that are driven in opposite phases. One member drives the shaving blade, while the other member can have a counterweight to suppress unwanted vibrations. The two movable members are connected to a spring element fixed to the stator.

  It is an object of the present invention to provide a drive mechanism for a small appliance that can generate as much vibration vibration as possible while preventing unwanted vibration of the appliance as much as possible.

  This object is achieved by a combination of functions in claim 1.

  The drive mechanism of the present invention for generating an oscillating motion of at least one actuating unit generates a magnetic field acting on a second drive member extending from the first drive member and movably disposed in the small appliance. The second drive member is oscillated and moved. The first drive member is movably disposed in the small electric appliance so as to oscillate in an opposite phase with respect to the second drive member. Further, since the drive mechanism has a coupling element, a rigid coupling is formed between the two drive members in a direction parallel to the operation direction of the two drive members, so that the two drive members operate in the operation direction. A flexible bond is formed in the orthogonal direction.

  Due to the antiphase in the oscillating motion of the two drive members, an extremely high relative speed of the drive members is obtained compared to a conventional drive mechanism in which only one drive member is activated and the other drive members are stationary. Since the efficiency of such a drive mechanism increases with the relative speed of the drive members, it is possible to achieve a higher efficiency with the drive mechanism of the present invention than comparable drive mechanisms known in the prior art. The structure of the coupling element according to the invention has the advantage, on the one hand, that it is possible to ensure a close-packed antiphase and a precise achievement of the predeterminable vibration amplitude relationship of the two drive members. On the other hand, the flexible coupling across the direction of movement of the two drive members simplifies the links on the drive members. Because no play is required. In view of the fact that the fixed arrangement with play involves a number of drawbacks, the coupling elements to the two drive members can be fixed without play within the scope of the invention. As a result, it is possible to obtain an advantage that it is configured to be compact at a low price and can be fixed without being affected by wear. Another advantage is that there is no noise, unlike fixed cases with play.

  In a preferred embodiment, the coupling element has one rigid element and a first spring element. The first spring element may be fixed to the rigid element and one of the two drive members. Furthermore, the coupling element generally has a second spring element, which is fixed to the rigid element and the other of the two drive members. Finally, the coupling element has a third spring element, which can be fixed to the rigid element and the frame. The first spring element and / or the second spring element and / or the third spring element are rigidly configured in a direction parallel to the operation direction of the two drive members, and are orthogonal to the operation direction of the two drive members. It can be configured elastically in the direction. The rigid element preferably has two separate members in parallel, the third spring member is fixed between these separate members, and the first and second spring elements are two of these separate members. Mounted on one free end. The separate member is particularly U-shaped. As described above, the coupling element can be used very simply and at a low price. Furthermore, the coupling member can be fixed to the two drive members without difficulty. This is because there is no need to meet tight tolerances and in each case the associated connection is a rigid connection.

  In order to provide the reversal of the direction of movement required for the anti-phase movement of the two drive members, the coupling element can be pivotally suspended. In this arrangement, the swivel axis is particularly positioned perpendicular to the direction of movement of the two drive members. If it is desired that the two drive members operate with the same vibration amplitude, the pivot axis is the center between the connection point of the coupling element to the first drive member and the connection point of the coupling element to the second drive member Can be arranged. In this connection, it is advantageous for the suspension of the coupling member to have a play-free structure. This is because in this way a high degree of precision can be achieved and no wear or noise problems occur. For this purpose, a fourth spring element can be fixed to the frame and the coupling element. Preferably, the fourth spring element is elastically configured in a direction parallel to the operation direction of the two drive members, and is rigidly configured in a direction orthogonal to the operation direction of the two drive members. Together with the spring element, it serves to pivotally suspend the coupling element from the frame. Thus, each pivoting movement of the coupling element is accompanied by some elasticity of the third and fourth spring elements and does not require a bearing arrangement consisting of members that are attached to each other for rotation. This results in the aforementioned advantages with regard to wear and noise manifestations as well as resistance to moisture (insensitivity).

The two drive members can be interconnected by at least one fifth spring element. The fifth spring element is elastically configured in a direction parallel to the operation direction of the two drive members. This has the advantage that the two drive members can be operated substantially without friction. At the same time, the restoring force required for the operation of the drive mechanism is also generated as a result. In particular, several fifth spring elements can be configured as stacked leaf springs , whereby a very high spring constant can be obtained, and the number of springs used can be adjusted accordingly. The spring constant can be easily changed by selection. Therefore, it is easy to set the resonance frequency of the drive mechanism to a desired value.

  In order to be able to fix the drive mechanism to a small appliance, the drive mechanism preferably has at least one sixth spring element, which is elastic in a direction parallel to the operating direction of the two drive members. It is configured. Thus, a frictionless suspension of the drive mechanism in the appliance is possible, and the sixth spring element has the additional advantage of separating the appliance from the drive mechanism with respect to vibration.

  The first spring element, the second spring element, the third spring element, the fourth spring element, the fifth spring element and / or the sixth spring element may each be configured as a leaf spring. The leaf spring generates an elastic force with respect to a single spatial direction. With respect to the other two spatial directions, the leaf spring acts like a rigid body and thus performs an additional static function in these spatial directions. Another advantage of the leaf spring is that it takes up little space and is available as a low cost product.

  At least one of the two drive members may have one or more permanent magnets. Furthermore, at least one of the two drive members may have a coiled core. With this arrangement, a powerful drive mechanism with sufficiently low power consumption can be obtained with relatively small dimensions, for example, allowing battery-powered operation of the small appliance of the present invention.

  In the operating state, the drive mechanism is configured such that the center of gravity of the first drive member including the cooperating member and the center of gravity of the second drive member including the cooperating member operate on a common line, particularly on a straight line. It is preferable. In this case, it is particularly advantageous that this line or straight line lies in the common operating plane of the two drive members (xz plane according to FIG. 1).

  It is also advantageous that the pivot axis of the coupling element intersects this line or straight line. Further, the drive mechanism may be configured such that, in the operating state, the linear moment of the first drive member including the cooperating member and the linear moment of the second drive member including the cooperating member are opposite and equivalent. Thereby, it is possible to prevent derivative angular moments and derivative linear moments that occur during operation of the drive mechanism. This has the advantage that no vibration is transmitted or practically transmitted to a small appliance in which the drive mechanism of the present invention is used.

  In the small appliance of the present invention, the frame is fixedly formed with the small appliance, so that all members attached on the frame can be supported on the small appliance. In order to ensure reliable and continuous operation and avoid manual adjustment, the miniature instrument of the present invention preferably has a self-learning electronic unit for controlling the drive unit under resonant conditions.

  The invention will now be described with reference to an embodiment relating to a drive mechanism for an electric shaver illustrated in the accompanying drawings. However, it will be appreciated that the present invention is also suitable for use in connection with other small appliances such as electric toothbrushes.

  FIG. 1 is a perspective view showing an embodiment of a drive mechanism according to the present invention. The drive mechanism of the present invention is configured as a linear vibration motor having two movable motor members 1 and 2. The two motor members 1 and 2 are arranged with a small relative distance. In order to facilitate the placement of the individual members on the two motor members 1 and 2, the motor members 1 and 2 are each shown separately. That is, the first motor member 1 is shown in FIG. 2, and the second motor member 2 is shown in FIG. The types of depiction are the same as in FIG.

A first motor member 1 illustrated in FIG. 2 includes an iron core 3 and a winding coil 4 disposed on the iron core 3. A first support structure 5 that functions to attach other members is attached on the iron core 3. The second motor member 2 illustrated in FIG. 3 has four permanent magnets 6 arranged in pairs on the common carrier plate 7. In each case, two permanent magnets 6 are arranged in parallel on the common carrier plate 7 with reverse parallel polarity. The carrier plate 7 is formed in a rod shape, and is formed of an iron material or other ferromagnetic material, like the iron core 3. The carrier plate 7 is fitted with a second support structure 8 that is used similarly to the first support structure 5 of the first motor member 1 for the purpose of fixing more members. Mounted on the second support structure 8 are two inner blades configured as a shaving blade 9. The shaving blade is driven by a linear motor and cooperates with an outer blade not shown, which is configured, for example, as a shaving foil. Further, the two resonance springs 10 are fixed to the first support structure and the second support structure by the screw 11 and the holding plates 12 on both sides of the motor members 1 and 2. In the illustrated embodiment, the resonant spring 10 is constructed as a bundle of a product seen overlapping leaf springs, each leaf spring is formed as a thin rectangular plate. In the plane in which these plates are spread, the plates act like a rigid body and produce elasticity in a direction perpendicular to the plane.

  The resonance spring 10 maintains the first motor member 1 and the second motor member 2 at a fixed distance from each other, and the distance is selected so that there is a small gap between the permanent magnet 6 and the iron core 3. Since the resonant springs 10 exhibit a spring action perpendicular to their main surface, the two motor members 1 and 2 have some degree of mobility in this direction, despite being fixed by the resonant springs 10, and therefore As a result, a vibration system formed by the two motor members 1 and 2 and the resonance spring 10 is obtained. In other words, when the first motor member 1 and the second motor member 2 bend and bend from the remaining position due to the action of a force that overcomes the restoring force of the resonance spring 10, the first motor member 1 and the second motor member Each of the two can perform a linear oscillating motion. In order to generate these oscillating motions, a current is passed through the coil 4. The coil 4 acts as an electromagnet and is assisted by the iron core 3 to generate a magnetic field that acts on the permanent magnet 6, resulting in relative movement of the coil 4 and the permanent magnet 6. In FIG. 1, this means that one of the two motor members 1 and 2 is bent to the left and the other is bent to the right along the X axis. Thus, the X axis according to FIG. 1 represents the horizontal axis and the Z axis represents the vertical axis.

  Through the activation of the appropriate coil 4, the polarity of the resulting magnetic field is reversed and the first and second motor members 1 and 2 are flexed alternately in one direction and then again in the other direction and finally reversed. It can vibrate in phase. In this context, an essential feature of the present invention is that both the first and second motor members 1 and 2 operate. That is, the linear motor does not have a stator used to drive the rotor, but has two opposingly vibrating motor members 1 and 2 that drive each other. One of these motor members 1 or 2 corresponds to the rotor of a conventional linear motor. Other motor members perform the function of a conventional linear motor stator, but unlike such a stator, it moves in a similar manner, not static. In particular, under other identical conditions, the result is that the first and second motor members 1 and 2 of the linear motor of the present invention move at twice the relative speed of the stator and rotor of the conventional linear motor. . A relatively high efficiency is achieved in this way.

  The frequency of the vibration movement of the two motor members is determined by the activation of the coil 4 and is specifically set to match the resonance frequency of the vibration system formed by the two motor members 1 and 2 and the resonance spring 10. This is done by a self-learning electronic unit, whereby the coil 4 is activated so that the vibration amplitude can be controlled by pulse width modulation. Under resonance conditions, a highly robust vibration action is obtained and only relatively little energy input is required.

  The linear motor of the present invention is configured so as to transmit vibration to the shaving device as much as possible due to its structure. In order to achieve this, it is necessary to make both the angular and linear moments resulting from the operation of the motor members 1 and 2 as zero as possible. When the center of gravity of the first motor member 1 including the cooperating member and the center of gravity of the second motor member 2 including the cooperating member operate on a common straight line, the derivative angular moment is zero. This is achieved in the embodiment illustrated in FIGS. This is because the first motor member 1 has a very compact structure and is surrounded by a somewhat larger second motor member 2 so that the second motor on the opposite end of the first motor member 1 This is because the mass distribution of the members 2 is adjusted mutually. For example, the shaving blade 9 is also considered in adjusting the mass distribution. Since the derived linear moment is zero, the linear moment of the first motor member 1 including the cooperating member and the linear moment of the second motor member 2 including the cooperating member must be opposite and equal. Don't be. Assuming that the vibration amplitude and frequency are the same, this condition is satisfied when the mass is equal, taking into account the cooperating members. In other words, it is necessary to adjust not only the mass distribution but also the numerical value of the total mass of the first and second motor members 1 and 2.

  In addition to the resonance spring 10, a holding spring 13 is fixed to each of the first support structure 5 and the second support structure 8 by the screw 11 and the holding plate 12. The holding springs 13 are similarly configured as leaf springs and take the form of a thin plate partially slit at two opposite ends, each holding spring 13 including two strips 14, each strip being a narrow bar 15 is connected to the holding spring body. Each strip 14 has a perforation 16 at its free end that is used to secure to the shaving device. Therefore, the linear motor of the present invention can be suspended elastically and contractively in the operating direction of the two motor members 1 and 2 on the shaving device by the holding spring 13. With this type of suspension, the shaving device is generally separated from the linear motor with respect to vibration.

  A further part of the linear motor essentially within the scope of the present invention is a coupling element 17, which mechanically connects the two motor members 1 and 2. This coupling is absolutely rigid in parallel to the direction of movement of the two motor members 1 and 2, and thus in the sense of synchronizing their relative movement in an accurate and permanent manner, this coupling is a resonant spring. 10 extends beyond the coupling realized. This synchronization is maintained even when the two motor members 1 and 2 are exposed to different loads, and the two motor members 1 and 2 are configured to vibrate in exactly opposite phases. As will be described in detail below, the coupling element 17 provides a flexible and non-rigid coupling in a direction perpendicular to the direction of movement of the motor members 1 and 2.

  The coupling element 17 has two U-shaped struts 18, which are arranged perpendicular to the direction of movement of the two motor members 1 and 2, so that the outside of each leg 19 of the two struts 18. The parts are adjacent. Fixed to the two other legs 19 are a first spring element 20 and a second spring element 21. They are each configured as a strip-shaped leaf spring and extend in a direction parallel to the operating direction of the two motor members 1 and 2. The first spring element 20 has a free end screwed to the first support structure 5. The second spring element 21 has a free end screwed to the second support structure 8. Sitting between two adjacent legs 19 of the strut 18 is a third spring element 22, which, like the first and second spring elements, is secured by welding. Is preferred. The third spring element is also configured as a strip-shaped leaf spring, and is positioned in parallel with the first spring element 20 and the second spring element 21. The third spring element is screwed into the frame 23 at its free end, and the frame has a perforation 24 for fixing to the shaving device. Screwed into the frame 23 is a fourth spring element 25, which is constructed in accordance with the first, second and third spring elements 20, 21 and 22 of the present invention. Differently, the longitudinal dimension is located in a direction orthogonal to the operation direction of the two motor members 1 and 2. The other end of the fourth spring element 25 is fixed to one of the struts 18 in the vicinity of the adjacent leg 19. This fixing is realized by screwing onto a mounting bracket 26 welded to one of the struts 18.

  The operation mode of the coupling element 17 will be described separately below.

  Through fixing to the first and second support structures 5 and 8 by the first and second spring elements 20 and 21, the coupling element 17 is like a rigid body in a direction parallel to the direction of movement of the two motor members 1 and 2. It acts like an elastic body in a direction perpendicular to it. On the one hand, this allows the phase relationship between the two motor members 1 and 2 to be accurately determined as described above. On the other hand, the spread of the struts 18 that changes with the movement of the two motor members 1 and 2 perpendicular to the movement direction can be compensated by its elasticity. According to the depiction in FIG. 1, during operation of the linear motor, the strut 18 performs alternating swinging motions left and right, with the result that the spread in the vertical direction changes continuously.

  In order to be able to cause a precise phase reversal of the two motor members 1 and 2 mentioned above via the coupling element 17, the pivot axis for the rocking movement of the coupling element 17 is determined as precisely as possible. Must be done. For this purpose, the strut 18 is fixed at one point by a third spring element 22 parallel to the direction of movement of the motor members 1 and 2 and by the fourth spring element 25 the direction of movement of the motor members 1 and 2. It is fixed orthogonally to. The point fixed in this way forms a pivot axis for the oscillating movement of the coupling element 17 and according to FIG. 1 is arranged in the center in the longitudinal dimension of the structure consisting of two struts 18. As a result of the pivot axis being placed at the center, the two motor members 1 and 2 vibrate with the same amplitude. If different vibration amplitudes of the two motor members 1 and 2 and thus different speed values are desired, an eccentric arrangement of the pivot axis can be selected instead. As a further singularity of the embodiment illustrated in FIG. 1, the pivot axis is a straight line along which the center of gravity of the motor member 1 and the center of gravity of the motor member 2 move, including the shaving blades driven by the motor members 1 and 2. Intersect. As a result, practically no unwanted vibration is transmitted to the shaving device.

  Furthermore, the embodiment illustrated in FIG. 1 is characterized in that all the members are connected without play, so that the individual interconnected members are rigidly fixed together at the connection location. The necessary freedom of movement between the connected individual members is achieved by means of leaf springs or leaf spring arrangements, so that even the pivot link is accomplished in the manner described above. As a result of such an approach, the linear motor of the present invention is obtained with extremely high accuracy, low friction, low wear and quiet operation.

  For example, carrier members such as the first support structure 5, the second support structure 8, the holding plate 12, the strut 18, the frame 23, and the mounting bracket 26 used in the linear motor of the present invention are sheet metal punching and bending members. Can be produced economically.

  In order to assemble the linear motor of the present invention, the individual members or assemblies that need to select precisely defined positions and / or orientations relative to each other are precisely aligned with each other, and this alignment for each single unit. Fixed in state.

It is a perspective view which shows the embodiment of the drive mechanism of this invention. It is a perspective view which shows the 1st motor member of the embodiment illustrated in FIG. It is a perspective view which shows the 2nd motor member of the embodiment illustrated in FIG.

Claims (28)

A coil for generating a magnetic field extending from the first drive member and acting on the second drive member, generating a vibrating motion of at least one actuation unit of the small appliance and movably disposed in the small appliance It said second driving member that is a driving mechanism for vibrating movement,
The first driving member is movably disposed in the small electric appliance so as to vibrate in an opposite phase with respect to the second driving member,
The drive mechanism has a coupling element, and the coupling element forms a rigid coupling between the two drive members in a direction parallel to the operation direction of the two drive members, and the two drive A flexible coupling is formed in the vertical axis direction of the small electric appliance perpendicular to the operation direction of the member,
Drive mechanism.   The drive mechanism according to claim 1, wherein the coupling element is fixed to the two drive members without play.   The drive mechanism according to claim 1, wherein the coupling element has one rigid element and a first spring element.   The drive mechanism according to claim 3, wherein the first spring element is fixed to the rigid element and one of the two drive members.   The drive mechanism according to claim 4, wherein the coupling element includes a second spring element fixed to the rigid element and the other of the two drive members.   The drive mechanism according to claim 3, wherein the coupling element includes a third spring element fixed to the rigid element and the frame. The first spring element, the second spring element, and / or the third spring element are rigidly configured in a direction parallel to an operation direction of the two drive members, and are in an operation direction of the two drive members. The drive mechanism according to any one of claims 3 to 6, wherein the drive mechanism is elastically configured in a vertical axis direction of the small electric appliance orthogonal to the vertical direction.   The rigid element has two struts arranged side by side, the third spring element is fixed between the struts, and the first spring element and the second spring element are two free ends of the strut The drive mechanism according to claim 6 or 7, wherein the drive mechanism is fixed to the drive mechanism.   The driving mechanism according to claim 8, wherein the strut has a U-shaped structure.   The drive mechanism according to claim 1, wherein the coupling element is suspended so as to be pivotable. The pivot axis of the coupling element is orthogonal to the horizontal axis direction of the small electric appliance parallel to the operation direction of the two drive members, and is also orthogonal to the operation direction of the two drive members. The drive mechanism according to claim 10, wherein the drive mechanism is positioned perpendicular to the vertical axis direction of the instrument.   12. A drive mechanism according to any one of claims 2 to 11, characterized in that a pivot axis is arranged at the center in the longitudinal dimension of the coupling element.   The driving mechanism according to any one of claims 10 to 12, wherein the coupling element is hung without play.   The drive mechanism according to any one of claims 6 to 13, wherein the fourth spring element is fixed to a frame and the coupling element. The fourth spring element, characterized in that the elastically constructed in two directions parallel to the direction of movement of the drive member is rigidly constructed in a direction perpendicular to the direction of movement of the two drive members The drive mechanism according to claim 14.   The two drive members are interconnected by at least one fifth spring element elastically configured in a direction parallel to an operation direction of the two drive members. The drive mechanism according to any one of 15. The drive mechanism according to claim 16, wherein the fifth spring element is configured as a stacked leaf spring .   For fixing to the small electric appliance, the drive mechanism has at least one sixth spring element elastically configured in a direction parallel to an operation direction of the two drive members. The drive mechanism according to any one of claims 1 to 17.   The first spring element, the second spring element, the third spring element, the fourth spring element, the fifth spring element, and / or the sixth spring element are configured as leaf springs, The drive mechanism according to any one of claims 3 to 18.   The drive mechanism according to any one of claims 1 to 19, wherein at least one of the two drive members includes at least one permanent magnet.   The drive mechanism according to any one of claims 1 to 20, wherein at least one of the two drive members has a core around which at least one coil is wound. In the operating state of the drive mechanism, the center of gravity of the first drive member including the cooperating member and the center of gravity of the second drive member including the cooperating member are on a common line or a common straight line. The driving mechanism according to any one of claims 1 to 21, wherein the driving mechanism operates.   23. The drive mechanism according to claim 22, wherein the line or the straight line is on a common operation surface of the two drive members.   24. The drive mechanism according to claim 22, wherein a pivot axis of the coupling element intersects the line or the straight line.   In the operating state of the drive mechanism, the linear moment of the first drive member including the cooperating member and the linear moment of the second drive member including the cooperating member are opposite and equivalent. The drive mechanism according to any one of claims 1 to 24.   A small electric appliance comprising at least one vibration actuating unit, wherein the small electric appliance includes the drive mechanism according to any one of claims 1 to 25.   27. The small appliance according to claim 26, wherein the frame is fixed to the small appliance. 28. The small appliance according to claim 26 or 27, wherein the driving mechanism is driven under a resonance condition .

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